Work carrier

ABSTRACT

A work carrier capable of moving a work stage  45  to an arbitrary position in the left/right direction and stopping the work stage  45  thereat with an accuracy equivalent to that of a conventional carrier or above through an inexpensive structure. The work carrier comprises a fixed guide rail member  15  and movable guide rail members  17, 18, 19  mounted on a supporting table  10,  a driver  16  for moving the movable guide rail members to the left and the right, rail member interlocking mechanisms  35   a,    35   b  for interlockingly operating the movable guide rail members  17, 18, 19,  and the work stage  45  mounted on the movable guide rail member  19,  wherein the driver  16  is a motor having a rotational speed being varied by inverter control and employing an open loop rotation control system, and a plurality of stopper members  52   a,    52   b,    52   c  are provided in order to stop the movable guide rail member  17  at a specified position.

TECHNICAL FIELD

The present invention relates to a work carrier with a plurality ofmovable guide rail members buckling laterally in multistage, which isused for carrying a work of a machine tool.

PRIOR ART

A work carrier as disclosed in Japanese Patent Publication No.1993-90760 has already existed. The work carrier comprises a fixed guiderail member mounted on a support table for left and right and threemovable guide rail members accumulated thereon. A servomotor is providedto displace the lowest movable guide rail member to the left/rightdirection. Besides, a rail member interlocking mechanism is provided tomake the upper movable guide rail members jut greatly to the left/rightdirection in connection with movement of the lowest movable guide railmember. Moreover, a work stage is provided so as to move in a left/rightdirection on the highest movable guide rail member in connection withits movement.

In this case, the servomotor is numerically controlled by a semi-closedloop rotation control system according to data of a rotation detectorfor detecting rotational displacement thereof before being inputted intoa reduction gear. Besides, its rotations are communicated to a mechanismfor interlocking the movable guide rail members and the work stagethrough the reduction gear.

The present invention aims to provide a work carrier capable ofdisplacing a work to an arbitrary position with an accuracy equivalentto that of a conventional carrier or above on following a basicstructure of the work carrier described in the Japanese PatentPublication No. 1993-90760 except for the servomotor.

SUMMARY OF THE INVENTION

To achieve the above-mentioned aim, a work carrier of the presentinvention is constructed as following. That is, the work carriercomprises a fixed guide rail member mounted on a support table for leftand right, at least more than two movable guide rail members accumulatedon the fixed guide rail member, a rotation drive unit for displacing thelowest movable guide rail member to the left/right direction through agear racking mechanism, a rail member interlocking mechanism foroperating so that the movable guide rail members may greatly jut toeither of the left and the right in an order from the lower inconnection with movement of either of the left and the right from itscenter of the lowest movable guide rail member, and a work stage movingin the left/right direction on the highest movable guide rail member inconnection with its movement. And therein, the drive unit serves as amotor having a rotational speed being varied by inverter control andemploying an open loop rotation control system. Besides, the drive unitis provided with a plurality of stopper members impacting each other tostop any of the 0 movable guide rail members at a position correspondingto a carrier starting point or a carrier finishing point of the workstage. The work stage is displaced to an arbitrary position between thecarrier starting point and the carrier finishing point.

In this invention, in case the work stage automatically stops at anarbitrary specified position between the carrier starting point and thecarrier finishing point, when it approaches at the specified position tobe stopped, the motor is controlled by the inverter control so as toreduce the rotational speed enough, and when it arrives there, the motoris controlled so as to reduce it to zero. Therefore, when the work stageapproaches at the specified position, it very slowly moves and exactlystops without receiving inertia force during its movement.

Since the stopper members impact each other at the carrier startingpoint and at the carrier finishing point to compulsorily stop the workstage, the work stage can stop more exactly.

The above-mentioned invention is defined as follows.

The stopper members comprise a movable stopper member fixed integrallywith the lowest movable guide rail member and a fixed stopper memberfixed integrally with the support table, so constructed that the lowestmovable guide rail member can stop at positions corresponding to thecarrier starting point and the carrier finishing point on impact betweenthe movable stopper member and the fixed stopper member.

Accordingly, it is unnecessary to provide with any stopper member to anyposition except for the lowest movable guide rail member and the supporttable. And, it becomes easy to secure and control a space for thestopper member.

Besides, a reduction gear, a driving pinion, a movable rack for left andright and a displacement detector are provided. Here, rotations of anoutput axis of the motor are inputted into the reduction gear. Thedriving pinion is interlockingly connected with the output axis of thereduction fear, and freely rotates at a specified position of thesupport table along its vertical surface. The movable rack for left andright is interlocked with the pinion and fixed on the lowest movableguide rail member. The displacement detector detects an operatingdisplacement of the output axis of the reduction gear on a path forcommunicating displacement based on the rotations of the motor or anoperating displacement of the arbitrary position by the side of acommunicating displacement terminus from the output axis.

According to this, the work stage is detected through the detector. Inthis case, since the detected results do not include errors caused bythe reduction gear which occasionally causes a large error to theoperating displacement of the work stage because backlash of a pluralityof gears are accumulated. Therefore, the work stage is exactlyposition-controlled through the detector in accordance with the detecteddata.

A tooth of the movable rack is inclined to front and rear within theface width thereof. Besides, the driving pinion serves as a bevel gearhaving a tooth to be interlocked to the tooth of the movable rack, fixedon the rotating central axis so as to changeably adjust a position inthe front/rear direction.

According to this, floating clearances in places where the tooth of thedriving pinion is interlocked with the tooth of the movable rackincrease or decrease by changing front and rear position of the drivingpinion.

Moreover, the rail member interlocking mechanism comprises a fixed racklong in the left/light direction, movable racks long in the left/rightdirection and interlocking pinions. Here, the fixed rack is fixed on thefixed guide rail member, and the movable racks are respectively fixed onthe movable guide rail members. And, the interlocking pinions aremounted at the specified places of the movable guide rail members exceptfor the highest movable guide rail member rotatively around axes forfront and rear. And therein, the movable rack or the fixed rack iscorrespondingly interlocked with the top or the bottom of eachinterlocking pinion. In this case, the tooth of the movable rack and thetooth of the fixed rack are inclined to the front/rear direction withinthe face width, and the interlocking pinions serve as bevel gears forinterlocking with the tooth of the movable rack. The axes for front andrear corresponding to the interlocking pinions are formed of fixed axesfor front and rear fixedly mounted on the corresponding movable guiderail members and eccentric cylindrical axis members external-insertedlyfixed thereon for changeably adjusting angles around them. Besides, theinterlocking pinions have the front and rear positions on thecorresponding axes for front and rear adjusted and changed,respectively.

In thus construction, the former clearance, which is the floatingclearance in the engaging position between the lower tooth of anarbitrary interlocking pinion and the tooth of the fixed rack or themovable rack, and the latter clearance, which is the floating clearancein the engaging position between the upper tooth of the interlockingpinion and the tooth of the movable rack, are mostly increased indifferent states each other by progress of time using the presentdevice. However, to cope with this, angle positions of the eccentriccylindrical axis members are exchanged to identify the former clearanceand the latter clearance, and besides, the arbitrary interlocking pinionis longitudinally displaced to the side where their clearances decrease.Therefore, both the former clearance and the latter clearance aredecreased in desirable sizes, respectively.

When the former clearance and the latter clearance are increased in asame size, their clearances are decreased in a desirable size only bylongitudinally displacing the arbitrary interlocking pinion to the sidewhere their clearances decrease.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view showing a process line with a work carrierrelated to the present invention, and

FIG. 2 is a right side view of the process line.

FIG. 3 is a front view showing a carrier start state and a carrierfinish state of the work carrier,

FIG. 4 is a front view showing an initial state of the work carrier, and

FIG. 5 is a partially vertical sectional view of the work carrier.

FIG. 6 shows an eccentric cylindrical axis member of the work carrier,FIG. 6A is a side view and FIG. 6B is a front view.

FIG. 7 shows a structure that an interlocking pinion is mounted to thework carrier, FIG. 7A is a plane view and FIG. 7B is a front view.

FIG. 8 is a sectional view at side sight, which shows the structure thatthe interlocking pinion is mounted on the work carrier, and

FIG. 9 is an explicative view showing position control of theinterlocking pinion.

FIG. 10 is a front view showing a state that stopper members are mountedon the work carrier,

FIG. 11 is a side view thereof and

FIG. 12 is a plane view thereof.

FIG. 13 is a plane view showing a modification of the state that stoppermembers are mounted on the work carrier.

PREFERRED EMBODIMENT OF THE INVENTION

FIGS. 1 to 13 show a process line with a work carrier related to thepresent invention. An embodiment of the present invention will beexplained as follows with reference to these drawings.

In FIGS. 1, 1A, 1B and 1C are three machining centers arranged at asuitable interval.

Each of machining centers 1A, 1B and 1C is so constructed that a column3 is fixed on the top of a base table 2, a spindle 4 is mounted on thecolumn 3 movably in a vertical, lateral and longitudinal direction, anda closed machining space 5 for machining a work w is formed upward thebase table 2 and forward the column 3 as shown in FIG. 2.

In this case, the closed machining space 5 is surrounded by left andright side walls 5 a, 5 b, a ceiling wall 5 c, a front wall 5 d shown inFIG. 2 and a standing cover for left and right 4 a formed forward thecolumn 3.

A work-fixing device 6 is provided in the closed machining space 5, andso constructed as to automatically cancel fixation of the fixed work wat arbitrary time. In thus cancelled state, when the work w is pushed upupward, it gets out of a not-illustrated work-positioning pin to befree. Work carriers H1, H2, H3, H4 related to the present invention arefixed on sides 5 a, 5 b of the base tables 2 of machining centers 1A,1B, 1C, respectively.

An explanation about one of these work carriers H1, H2, H3, H4 will beas follows. Numeral 7 is a fixed table having a rectangular frame shapelong in the left/right direction, which is fixedly bolted to the basetable 2 through coupling members 8. A general motor 9 (a lead motor) forclimbing-driving is vertically fixed on the top of the fixed table 7. Asupport table 10 vertically operates through a vertical feed mechanism11 by rotations of the motor 9. The vertical feed mechanism 11 is shownin FIG. 3 and so on.

The vertical feed mechanism 11 comprise a vertical thread axis 12, a nutbody 13 and a pair of left and right vertical guide rails 14, 14 asshown in FIGS. 2, 3. The vertical thread axis 12 rotates at a fixedheight position due to the motor 9. The nut body 13 is integrally fixedon the support table 10, and the vertical tread axis 12 is screwedtherein. The vertical guide rails 14, 14 are fixed on the fixed table 7and guide the support table 10 in a vertical direction.

On the support table 10, as shown in FIGS. 3 to 5, are fixed ahorizontal fixed guide rail member 15 long in a left/right direction f1and a crossfeed general motor 16 (a lead motor) toward a front/reardirection f2. Three movable guide rail members 17, 18, 19 areaccumulated over the fixed guide rail member 15. Each of them is guidedto any of the just lower fixed guide rail member 15 or movable guiderail members 17, 18 displaceably in the left/right direction f1.

In this case, as shown in FIG. 5, the fixed guide rail member 15comprises a rail body for left and right 15 a, a member 15 b forsupporting the rail member 15 a and a member 15 c for combining themember 15 b with the support table 10. The movable guide rail member 17comprises a rail member for left and right 17 a, a member 17 b forsupporting the rail member 17 a, a member 17 c fixed on the front of themember 17 b and a channel member 17 d fixed on the bottom of the member17 c and guided to the rail member 15 a. The movable guide rail member18 comprises a channel member 18 a, a member 18 b for supporting thechannel member 18 a and a channel member 18 c fixed on the bottom of themember 18 b to be guided the rail member 17 a. The movable guide railmember 19 comprises a rail member for left and right 19 a, a member 19 bfor supporting the rail member 19 a and a rail member for left and right19 c fixed on the bottom of the member 19 b to be guided to the channelmember 18 a. The rail members 15 a, 17 a, 19 c and the channel members17 d, 18 c, 18 a to be interlocked therewith are smoothly-relativelydisplaced through a large number of balls.

In FIGS. 2, 5, the lowest movable guide rail member 17 is driven to theleft/right direction f1 by the general motor 16, and it is explained indetail as follows.

A reduction gear 20 for being inputted rotations of the motor 16 isfixedly mounted on the rear of the general motor 16 shown in FIG. 2through a fitting member 21 fixed on the support table 10 as shown inFIG. 5. A bearing 23 is fixedly mounted on the rear side f4 of thereduction gear 20 through a fitting member 22 fixed on the bottom of themember 15 b composing the fixed guide rail member 15. In this case, thebearing 23 is provided with a cylindrical member 24 integrally fixedwith the fitting member 22 and a pair of front and rear ball bearings25, 25 mounted inside the cylindrical member 24.

A rotating central axis for front and rear 26 is mounted on the bearing23 through the bearings 25, 25 rotatively at a fixed position. The frontend of the rotating central axis 26 is combined with an output axis 20 athrough a universal coupling 26 a absorbably in center displacement, anda driving pinion 27 is fixed on the rear end the rotating central axis26 changeably in its front and rear position. In this case, 28 is acylindrical male wedge whose flange is provided with a thread hole 28 ainto which a push bolt is screwed and a through hole 28 b into which afixed bolt 29 screwed to the driving pinion 27 is inserted. Numeral 28Ais a cylindrical female wedge changeably in enlarging diameter, which isexternally interfitted to the cylindrical male wedge 28. The drivingpinion 27 forms in bevel gear, and an inclination θ1 of face width ofthe top of the tooth 27 a, namely, the front/rear direction f2 is about10 degree as compared with a horizontal plane.

On the other hand, a board member 30 a long in the left/right directionf1 is fixed on the bottom of the member 17 c composing the lowestmovable guide rail member 17 along the horizontal plane. A verticalboard member 30 b long in the left/right direction f1 is fixed on thelower front edge of the board member 30 a. And besides, a plurality ofvertical reinforcing aggregate members 30 c are fixed on the bottom ofthe board member 30 a at the rear side f4 of the board member 30 b. Afixture member 30 d long in the left/right direction f1 is fixed on thelower end of the aggregate member 30 c and the lower end of the boardmember 30 b along the horizontal plane. And a downward movable rack 31long in the left/right direction f1 is fixed on the bottom of thefixture member 30 d. The top of the tooth 31 a of the rack 31 isinclined in the front/rear direction of face width in connection withthe tooth 27 a of the driving pinion 27, and this inclination θ2 isabout 10 degree as compared with the horizontal plane as same as thecase of the driving pinion 27. The tooth 31 a of the movable rack 31 isinterlocked to the tooth 27 a of the driving pinion 27, and a floatingclearance in the interlocking between the tooth 31 a and the tooth 27 a(backlash and so on) is adjusted to less than 0.04 mm when the tooth 31a and the tooth 27 a are opposite.

The floating clearance is adjusted and changed in the manner of varyingthe height of the movable rack 31 to the lowest movable guide railmember 17 due to varying the thickness of an adjustable shim or in themanner of varying the front and rear position of the driving pinion 27against the rotating central axis 26.

In thus construction, the rotations of the motor 16 are transmitted tothe reduction gear 20. And thus reduced rotations are transmitted to therotating central axis 26 and the driving pinion 27. Then, rotations ofthe driving pinion 27 interlockingly displace the lowest movable guiderail member 17 to the left/right direction through the movable rack 31.In this case, the lowest movable guide rail member 17 is smoothlydisplaced linearly in the left/right direction on a specified positiondue to guiding actions of the guide rail member 15 a, the channel member17 d and globes inserted therebetween.

As shown in FIGS. 2 and 3, a rotary encoder 32 of displacement detectorfor detecting number of rotations of the rotating central axis 26 isprovided below the driving pinion 27 integrally with the support table10. An input axis 32 a of the rotary encoder 32 is interlockinglyconnected with the rotating central axis 26 through a gear transmittingmechanism comprising a driving gear 33 a and a driven gear 33 b. In thiscase, the driving gear 33 a is fixed on the rotating central axis 26,and the driven gear 33 b is fixed on the input axis 32 a.

As shown in FIG. 5, the fixed guide rail member 15 and the movable guiderail members 17, 18, 19 are interlockingly connected with one anotherthrough rail member interlocking mechanisms 34 a, 34 b. Here, the railmember interlocking mechanisms 34 a, 34 b operate so that the upper oneof movable rail members 17, 18, 19 protrudes more greatly in theleft/right direction f1 in connection with the displacement of themovable guide rail member 17. The rail member interlocking mechanisms 34a, 34 b will be explained as follows.

As shown in FIGS. 3 to 6, interlocking pinions 35 a, 35 b are rotativelymounted on the centers of the movable guide rail members 17, 18 in thelateral direction through the axes for front and rear 36 a, 36 b and apair of front and rear bearings, respectively. Either of theinterlocking pinions 35 a, 35 b is formed in a bevel gear in accordancewith the driving pinion 27. An inclination θ3 of face width of the topof the tooth is about 10 degree as compared with the horizontal plane.

A downward movable rack 37 long in the left/right direction and anupward fixed rack 38 long in the left/right direction f1 are interlockedwith the top and the bottom of the interlocking pinion 35 a mounted onthe lowest movable guide rail member 17, respectively. The movable rack37 is fixed on the lower front edge of the member 18 b composing themiddle movable guide rail member 18. The fixed rack 38 is fixed on thetop of the member 15 c composing the fixed guide rail member 15. The topof the tooth of each racks 37, 38 is inclined in the front/reardirection of face width in connection with the tooth of the interlockingpinion 35 a. This inclination is in about 10 degree as compared with thehorizontal plane as well as the interlocking pinion 27.

Besides, a downward movable rack 39 long in the left/right direction f1and an upward fixed rack 40 long in the left/right direction f1 areinterlocked with the top and the bottom of the interlocking pinion 35 bof the middle movable guide rail member 18, respectively. The movablerack 39 is fixed on the lower rear edge of the member 19 b composing thehighest movable guide rail member 19. The fixed rack 40 is fixed on thetop of the member 17 c composing the lowest movable guide rail member17. The top of each tooth of these racks 39, 40 is inclined in thefront/rear direction of face width in accordance with the tooth of theinterlocking pinion 35 b. This inclination is in about 10 degree ascompared with the horizontal plane as well as the interlocking pinion 36a.

The axes for front and rear 36 a, 36 b rotatively supporting theinterlocking pinions 35 a, 35 b are formed of fixed axes for front andrear 41 a and eccentric cylindrical axis members 41 b. Here, the fixedaxes 41 a are screwed in and fixed on the members 17 b, 18 b of thecorresponding movable guide rail members 17, 18 and the eccentriccylindrical axis members 41 b are externally inserted to the fixed axes41 a and changeably adjust angles around them. Besides, the interlockingpinions 35 a, 35 b changeably adjust the front and rear positions on thecorresponding axes 36 a, 36 b due to varying the thickness of athickness control ring 42 externally inserted to the eccentriccylindrical axis members 41 b, respectively.

In this case, the fixed axes 41 a include head parts for preventing theeccentric cylindrical axis members 41 b from slipping out and threadparts for being screwed in the movable guide rail members. As shown inFIG. 6, the eccentric cylindrical axis member 41 b comprises a rightcircular peripheral part a and a straight cylindrical hole b. Here, acentral line of the straight cylindrical hole b is what parallelydisplaces a central line of the peripheral part a to the radialdirection, for example, by about 0.1 mm. Besides, the eccentriccylindrical axis member 41 b has a flange part c and a short rightcircular peripheral part d1 concentrically with the cylindrical hole bat the front edge, and a short right circular peripheral part d2concentrically with the cylindrical hole b at the bottom edge.

The tips of the axes for front and rear 36 a, 36 b are supported to aframe member 43 in angular C letter shape at plane view, which is fixedon the movable guide rail members 17, 18 through bolts 44A shown in FIG.7. The frame member 43 has a through hole 43 a for being interfitted theright circular peripheral part d1 at the center of the lateral length,and three comparatively small through holes e1, e2, e3 for beinginserted bolts 44 which are alternatively screwed in thread holes c1,c2, c3 formed to the flange c of the eccentric cylindrical axis member41 b as shown in FIG. 6B.

Each tooth of the interlocking pinions 35 a, 35 b is interlocked witheach tooth of movable racks 37, 39 or the fixed racks 38, 40. Thefloating clearance (backlash and so on) of the tooth is adjusted so asto be less than 0.04 mm under a basic state (as shown in FIG. 9C) wherevertical eccentricities of the interlocking pinions 35 a, 35 b againstthe centers of the fixed axes 41 a are zero.

In thus constructed rail member interlocking mechanisms 34 a, 34 b inFIG. 5, when the lowest movable guide rail member 17 is situated at thecenter (neutral point) p0 of the length in the left/right direction f1of the support table 10 as shown in FIG. 4, the other movable guide railmembers 18, 19 are situated at neutral points p1, respectively. When thelowest movable guide rail member 17 is displaced to either of theleft/right direction f1, the fixed rack 38 rotates the interlockingpinion 35 a around the axis 36 a based on relative displacement betweenthe movable guide rail member 17 and the fixed guide rail member 15. Therotation of the interlocking pinion 35 a displaces the movable rack 37fixed on the middle movable guide rail member 18 to the displacementdirection of the lowest movable guide rail member 17 together with themovable guide rail member 18. Then, the fixed rack 40 rotates theinterlocking pinion 35 b mounted on the middle movable guide rail member18 around the axis 36 b based on the relative displacement between themiddle movable guide rail member 18 and the lowest movable guide railmember 17. The rotation of the interlocking pinion 35 b displaces themovable rack 39 fixed on the highest movable guide rail member 19 to thedisplacement direction of the middle movable guide rail member 18together with the movable guide rail member 19. According to thusdisplacement, the movable guide rail members 17, 18, 19 jut toward theirdisplacement direction more greatly in due orders from the lower asshown in FIG. 3.

As shown in FIG. 5, a work stage 45 is guided to the highest movableguide rail member 19 through the rail member 19 a displaceably in theleft/right direction f1. The work stage 45 comprises a table member 45 ahaving a plane top, an underside-supporting member 45 b arranged belowthe table member 45 a, a pair of front and rear binding members 45 c, 45c combining these members 45 a, 45 b, and a channel member 45 d. Thechannel member 45 d is fixed on the center in the front/rear directionof the bottom of the underside-supporting member 45 b, and besides,guided in the left/right direction f1 through the rail member 19 a.

Between the work stage 45 and the highest movable guide rail member 19,is provided a chain interlocking mechanism 46 for displacing the workstage 45 in connection with the lateral displacement of the movableguide rail member 19.

In the chain interlocking mechanism 46, a pair of front and rear and apair of left and right sprockets 48, 48 are mounted on left and rightends of the highest movable guide rail member 19 rotatively around thesupporting axes 47, 47 as shown in FIGS. 4, 5. In the front and rear ofthe movable guide rail member 19, a pair of left and right chains 49, 49are hung and turned to the corresponding sprockets 48, 48 in horizontalU letter shape. The underside edges of the chains 49, 49 are fixed abouton the center of the lateral length of the highest movable guide railmember 19 through chain fixing blocks 51. Besides, the upside edgesthereof are fixed on the underside-supporting member 45 b throughtensile fixtures 51 as the chains 49, 49 receive tension by springs.When the highest movable guide rail member 19 is displaced to one sideof the left/right direction f1, the chains 49, 49 at the front and rearof the movable guide rail member 19 are stretched by the chain fixingblocks 50 and displace the work stage 45 to the displacement direction.On the other hand, the other side chains 49, 49 at the front and rear ofthe movable guide rail member 19 are stretched by the tensile fixtures51 to be displaced.

As shown in FIG. 3, when the highest movable guide rail member 19 isdisplaced to the right by a fixed length, the work stage 45 arrives at acarrier starting point p1. Conversely, when it is displaced to the leftby a fixed length, the work stage 45 arrives at a carrier finishingpoint p2. Besides, an impact stopper means comprising a plurality ofstopper members 52 a, 52 b, 52 c is provided to prevent the work stage45 from being displaced to right or left over these points p1, p2 afterarriving at the carrier starting point p1 or the carrier finishing pointp2 from the neutral point p0, as shown in FIG. 4.

Among a plurality of stopper members 52 a, 52 b, 52 c, the stoppermembers 52 a, 52 b serve as movable stopper members fixed integrallywith the lowest movable guide rail member 17, and the stopper member 52c serves as a fixed stopper member fixed integrally with the supporttable 10. In this case, the movable stopper members 52 a, 52 b form intoa rectangular parallelepiped for front and rear, and as shown in FIGS.10 to 12, they are fixed on the outsides of fixtures 53, 53 so as to jutin the forward f3 through two bolts 55, 55 and a shim 54 for adjustingposition in the left/right direction. Here, the fixtures 53, 53 arefixed on the tops of the left and right edges of the fixture member 30 dintegrally with the lowest movable guide rail member 17. Besides, thefixed stopper member 52 c forms into a rectangular parallelepiped forleft and right, fixed on the front edge of the center of the laterallength of the member 15 b forming the fixed guide rail member 15 throughtwo bolts 59, 59.

In thus impact stopper means, when the lowest movable guide rail member17 is displaced to the right from the neutral point p0 and arrives at aposition corresponding to the carrier starting point p1 of the workstage 45, the forward right side face of the left movable stopper member52 a impacts against the left end face of the fixed stopper member 52 c.Therefore, the movable guide rail member 17 is regulated from furtherright displacement. Besides, when the lowest movable guide rail member17 is displaced to the left from the neutral point p0 and arrives at aposition corresponding to the carrier finishing point p2 of the workstage 45, the forward left side face of the right movable stopper member52 b impacts against the right edge face of the fixed stopper member 52c. And therefore, the movable guide rail member 17 is regulated fromfurther left displacement.

A controller 56 comprising a control circuit mechanism 56 a of thegeneral motor 9 and a control circuit mechanism 56 b of the generalmotor 16 is provided on the fixed table 7 of each work carrier as shownin FIG. 2. A control system in the control circuit mechanisms 56 a, 56 bis an open loop system as shown in the following.

The control circuit mechanism 56 a is constructed so as to verticallydisplace the support table 10 due to controlling the general motor 9 andstop it at a descent point p4 and an ascent point p5 in FIG. 1.

The control circuit mechanism 56 b is constructed so as to stop the workstage 45 at the carrier starting point p1 and the carrier finishingpoint p2 and besides an arbitrary position therebetween due tocontrolling the general motor 16 based on data detected by the rotaryencoder 32. In this case, to exactly stop the work stage 45 at anarbitrary desirable specified position, the general motor 16 hasrotations controlled based on an inverter control. For example, adriving current of the motor 16 is 30 cycle/second in an ordinal carrierspeed of the work stage 45, and it is decreased in 9 cycle/second at astroke when the work stage 45 approaches to the specified position.Besides, when the work stage 45 arrives there, the driving current ismade in 0 cycle/second.

Next, an operating example of thus constructed machining line will beexplained as follows.

When all parts are capable of automatic operation, the work carriers H1to H4 in FIG. 1 keep an initial condition where the support table 10 issituated in the descent point p4 and the movable guide rail members 17,18, 19 are situated in the neutral point p0. Then, the work w is fed toa fixed height of the carrier starting point of the first work carrierH1 by a not-illustrated arbitrary feed means, an operation startingcommand is inputted in the controller 56 of the work carrier H1 from anot-illustrated central controller.

Accordingly, all parts of the work carrier H1 operate as follows. Whenthe support table 10 is situated in the descent point p4, the work stage45 is displaced to the right from the neutral point p0 by the motor 16and arrives at the carrier starting point. Here, the support table 10 isdisplaced to the ascent point p5 by the motor 9. During thisdisplacement, the work stage 45 receives the work w situating to thefixed height of the carrier starting point. Then, it is displaced to theleft by the motor 16 and arrives at the carrier finishing point as thesupport table 10 keeps in the ascent point p5. Here, the support table10 is displaced to the descent point p4 by the motor 9. During thisdisplacement, the work w on the work stage 45 is received by thepublic-known work-fixing device 6 inside the first machining center 1Aand positionally fixed.

Thereafter, the work stage 45 is displaced to the right by the motor 9and stops at the neutral point p0 as the support table 10 keeps in thedescent point p4. This stopping state is kept until the next work iscarried.

In the operation of thus work carrier H1, the present position of thework stage 45 in the left/right direction is judged according to thedata detected by the rotary encoder 32. When the work stage 45 is judgedto arrive near the carrier finishing point, the carrier starting pointor the other stopping position, 9 cycle/second of the driving current isfed into the general motor 16 to rotate at extremely low speed. Besides,when the work stage 45 is judged to arrive there, 0 cycle/second of thedriving current is fed into the motor 16 until the next left and rightdisplacement to stop the rotations. Accordingly, the work stage 45 canbe exactly and swiftly stopped at the carrier finishing point, thecarrier starting point or the other stopping position.

In this case, since an overrun regulating operation due to the impactbetween the movable stopper member 52 a or 52 b and the fixed stoppermember 52 c is added to the carrier starting point or the carrierfinishing point, the work stage 45 is exactly and swiftly stopped within±0.4 mm of the lateral error. Besides, in case of the other stoppingposition, it is exactly and swiftly stopped within ±0.6 mm of thelateral error.

Here, the work w fixed on the work-fixing device 6 in the firstmachining center 1A has the first machining enforced. When the machiningis finished, an operation starting command is inputted to the controller56 of the second work carrier H2 from the not-illustrated centralregulating device.

Accordingly, all parts of the second work carrier H2 operate inaccordance with the first work carrier H1. When the support table 10keeps in the descent point p4, the work stage 45 is displaced to theright and arrives at the carrier starting point. Here, the support table10 is displaced to the ascent point p5. During this displacement, thework stage 45 receives the work w not fixed by the work-fixing device 6in the first machining center 1A Then, the work stage 45 is displaced tothe left as the support table 10 is situated at the ascent point p5 andarrives at the carrier finishing point. Here, the support table 10 isdisplaced to the descent point p4. During this displacement, the work won the work stage 45 is received by the work-fixing device 6 in thesecond machining center 1B and positionally fixed. Thereafter, the workstage 45 is displaced to the right and stops at the neutral point p0.The stopping state is kept until the next work is carried.

Then, after the second work carrier H2 returns to the initial condition,the first work carrier H1 is allowed to carry and operates according tothe operation starting command from the not-illustrated centralregulating device similarly.

Here, the work w fixed on the work-fixing device 6 in the secondmachining center 1B has the second machining enforced. When themachining is finished, an operation starting command is inputted to thecontroller 5G of the third work carrier H3 from the not-illustratedcentral regulating device.

Accordingly, all parts of the third work carrier H3 operate inaccordance with the second work carrier H2. The work w on thework-fixing device 6 in the second machining center 1B is fixed on thework-fixing device 6 in the third machining center 1C. Thereafter, thethird work carrier H3 returns and stops to the initial condition, andthe stopping state is kept until the next work is carried.

Then, after the third work carrier H3 returns to the initial condition,the second work carrier H2 is allowed to carry and operates according tothe operation starting command from the not-illustrated centralregulating device similarly.

The work w fixed on the work-fixing device 6 in the third machiningcenter 1C has the third machining enforced. When the machining isfinished, an operation starting command is inputted to the controller 56of the fourth work carrier H4 from the not-illustrated centralregulating device. Accordingly, all parts of the fourth work carrier H4operate in accordance with the second work carrier H2. The work w on thework-fixing device 6 in the third machining center 1C is carried out atthe fixed height of the carrier finishing point of the fourth workcarrier H4.

Then, after the fourth work carrier H4 returns to the initial condition,the third work carrier H3 is allowed to carry and operates according tothe operation starting command from the not-illustrated centralregulating device similarly.

Besides, the fourth work carrier H4 under the initial condition has thecarrier operation allowed after the work w carried out to the specifiedheight of the carrier finishing point is displaced to differentposition. And, it operates according to the operation starting commandfrom the not-illustrated central regulating device similarly.

Thus operations are repeated, and therefore, the work carrying and thework machining in the machining line are to be automatically performed.

When using time for the work carriers H1 to H4 in the machining line haspassed, the floating clearance increases in an interlock between thedriving pinion 27 and the movable rack 31, an interlock among theinterlocking pinion 35 a, the movable rack 37 and the fixed rack 38, andan interlock among the interlocking pinion 35 b, the movable rack 39 andthe fixed rack 40.

When the floating clearance increases, the work stage 45 misses theexactness for stopping position in the left/right direction.Accordingly, for example, when the floating clearance surpass 0.04 mm,the above-mentioned interlock needs to be adjusted so that it becomesless than 0.04 mm.

Management for this adjustment will be explained as follows.

First of all, when the floating clearance in the interlock between thedriving pinion 27 and the movable rack 31 increases, its management willbe explained. In FIG. 5, when the fixed bolt 29 is pulled out, anot-illustrated push-bolt is screwed in the bolt hole 28 a and thecylindrical male wedge 28 is pulled and displaced from the drivingpinion 27, thereby loosening fastening of the driving pinion 27 for therotating central axis 26. Next, the driving pinion 27 is displaced tothe forward f3 on the rotating central axis 26. As this displaceddistance increases, the floating clearance gradually decreases inconnection with the longitudinal inclinations of the tooth 27 a and thetooth 31 a. Then, when the floating clearance becomes less than 0.04 mm,the fixed bolt 29 is screwed, and the cylindrical male wedge 28 isjammed into the driving pinion 27 to fasten the driving pinion 27 to therotating central axis 26.

Besides, in stead of thus management, the height of the movable rack 31can be made suitably low by interposing a not-illustrated shim betweenthe movable rack 31 and the plate member 30 d.

When the floating clearance in the interlock among the interlockingpinion 35 a, the movable rack 37, and the fixed rack 38 increases, thefollowing management will be performed.

First of all, the interlocking pinion 35 a is suitably displaced to therearward f4 against the movable rack 37 and the fixed rack 28.Therefore, the frame member 43 and the fixed axis for front and rear 36a are removed, and the adjustable ring 42 is taken out and machined sothat its thickness is suitably decreased. And then, the fixed axis 36 ais re-fastened to combine all parts in the original state. According tothis, the position of the interlocking pinion 35 a changes by a decreasein the thickness of the adjustable ring 42, and the floating clearancein the upper and lower interlock decreases in connection with thelongitudinal inclination of the tooth related to the interlock.

Since the floating clearance in the interlock between the interlockingpinion 35 b and the upper movable rack 37 is usually different from thatbetween the interlocking pinion 35 b and the lower fixed rack 38, theupper and lower floating clearances are managed so as to agree.Therefore, the bolt 44 is pulled out, the eccentric cylindrical axismember 41 b is rotatively displaced to a suitable direction around thefixed axis for front and rear 41 a, the bolt 44 is re-screwed, and thus,the eccentric cylindrical axis member 41 b is fixed on a suitable angleposition.

In this case, when the lower floating clearance is larger than the upperfloating clearance and the difference therebetween is comparativelysmall, as shown in FIG. 9B, the bolt 44 is inserted into the throughhole e2 at the specified position of the frame member 43 and screwed inthe thread hole c3 at the specified position of the flange c of theeccentric cylindrical axis member 41 b. According to this, the eccentriccylindrical axis member 41 b is fixed as it is rotated right from thestandard position shown in FIG. 9A by a comparative large angle.

On the other hand, when the upper floating clearance is larger than thelower floating clearance, the eccentric cylindrical axis member 41 b isrotated left therefrom and managed symmetrically with theabove-mentioned case. In this way, the upper and lower floatingclearances are made to closely resemble and less than 0.04 mm.

Besides, in stead of thus management, the heights of the movable rack 37and the fixed rack 38 can be made to closely resemble in that of theinterlocking pinion 35 a by interposing shims between the movable rack37 and the member 18 b as well as between the fixed rack 38 and themember 15 c.

When the floating clearance in the interlock among the interlockingpinion 35 b, the vertical movable racks 39 and the fixed rack 40increases, its management is substantially same as the management whichis performed when the floating clearance in the interlock among theinterlocking pinion 35 a, the movable rack 37 and the fixed rack 38increases. Accordingly, it will be performed in accordance with thismanagement.

The above-mentioned example can be modified as follows.

The lateral displacement of either of the movable guide rail members 18,19 or the work stage 45 may be regulated by changing the places forfixing the stopper members 52 a, 52 b, 52 c. In this case, a stoppermember may be provided between arbitrary two members among the movableguide rail members 18, 19 and the work stage 45 or between an arbitrarymember among them and a place integrally with the support member 10 soas to impact each other.

In stead of the above-mentioned stopper members 52 a, 52 b, a structureas shown in FIG. 13 can be done. That is, a member for front and rear 57is fixed on each fixture 53, bolts for left and right serving as thestopper members 52 a, 52 b are screwed in the front ends of the members57, 57, and lock nuts 58, 58 are screwed in the bolts 52 a, 52 b tofasten displacements thereof. According to this, it becomes easy toadjust the position of stopper members 52 a, 52 b.

Besides, in stead of the movable guide rail members 17, 18, 19 intriple, the middle movable guide rail member 18 can be made more thantwo stairs so as to form in more than quartet. In this case, the upperand lower contacting ones among these members are interlockinglyconnected in accordance with the interlocking connection among theinterlocking pinion 35 b, the movable rack 39 and the fixed rack 40. Andwhen the lowest movable guide rail member 17 is laterally displacedagainst the fixed guide rail member 15, all movable guide rail membersare interlocked so that the upper juts out more greatly to theleft/right direction.

Moreover, it can be so constructed that the position of the eccentriccylindrical axis member 41 b around the fixed axis for left and right 41a is modified in no stairs.

INDUSTRIAL APPLICABILITY

According to the present invention, even if the general motor 16 is usedin stead of the conventional servomotor, the work stage 45 can bedisplaced to the arbitrary position on the left/right direction withaccuracy more than the equal against the conventional one. Concretely,for example, the work stage 45 can stop at the carrier starting point p1and the carrier finishing point p2 with accuracy within ±0.4 mm, andbesides, at the arbitrary position therebetween with accuracy within the±0.6 mm.

Besides, it is unnecessary to provide with the stopper members 52 a, 52b, 52 c to the place except for the lowest movable guide rail member 17and the support table 10. Therefore, it is possible to secure a spacefor the stopper members 52 a, 52 b, 52 c easily, and it can be soconstructed that the position can be adjusted in a wide place.

Moreover, it is possible to exactly stop the work stage 45 at thearbitrary position based on the data detected by the detector 32regardless of the floating of the transmitting part of the reductiongear 20.

Furthermore, it is possible to easily increase and decrease the floatingclearance in the interlock between the tooth 27 a of the driving pinion27 and the tooth 31 a of the movable rack 31 due to modifying thelongitudinal position of the driving pinion 27.

Besides, it is possible to decrease both of the floating clearance inthe interlock between the lower tooth of an arbitrary interlockingpinion 35 a or 35 b and the tooth of the fixed rack 38 or the fixed rack40 and the floating clearance in the interlock of the upper tooth of thearbitrary interlocking pinion 35 a or 35 b and the tooth of the movableracks 37, 39 in desirable size.

1. A work carrier, comprising: a fixed guide rail member for left andright provided on a support table; at least more than two movable guiderail members accumulated on the fixed guide rail member; a drive unitfor displacing the lowest movable guide rail member in a left/rightdirection; a rail member interlocking mechanism for operating so that anupper movable guide rail member may greatly jut to the left/rightdirection in connection with movement of the lowest movable guide railmember in the left/right direction; and a work stage moving in theleft/right direction on the highest movable guide rail member inconnection with its movement, wherein the drive unit serves as a motorhaving a rotational speed being varied by inverter control and employingan open loop rotation control system, a plurality of stopper members areprovided so as to impact each other to stop any of the movable guiderail members at positions corresponding to a carrier starting point anda carrier finishing point of the work stage, and the work stage isdisplaced to an arbitrary position between the carrier starting pointand the carrier finishing point.
 2. A work carrier as claimed in claim1, wherein said plurality of stopper members comprise movable stoppermembers 52 a, 52 b fixed integrally with the lowest movable guide railmember 17 and a fixed stopper member 52 c fixed integrally with asupport table 10, and the lowest movable guide rail member is stopped atpositions corresponding to a carrier starting point p1 and a carrierfinishing point p2 on impact of the movable stopper members and thefixed stopper member.
 3. A work carrier as claimed in claim 1, whereinsaid work carrier comprises a reduction gear 20 for being inputtedrotation of an output axis of said motor, a driving pinion 27interlockingly connected with an output axis 20 a of the reduction gear20 and freely rotated along a vertical surface for left and right at aspecified position of the support table 10, a movable rack 31 long in aleft/right direction interlocked with the pinion and fixed on the lowestmovable guide rail member, and a displacement detector 32 for detectingan operating displacement of the output axis of the reduction gear on apath for communicating an operating displacement based on the rotationof the motor or an operating displacement in the arbitrary position bythe side of a communicating displacement terminus from the output axis.4. A work carrier as claimed in claim 3, wherein a tooth 31 a of themovable rack is inclined in a front/rear direction of face width, andthe driving pinion 27 serves as a bevel gear having a tooth 27 a to beinterlocked with the tooth of the movable rack, and said driving pinion27 is fixed on a rotating central axis 26 to adjust a position in thefront/rear direction.
 5. A work carrier as claimed in claim 1, whereinsaid rail member interlocking mechanism is provided with a long fixedrack in a left/right direction fixed on said fixed guide rail member,movable racks long in a left/right direction respectively fixed on saidmovable guide rail members, and interlocking pinions 35 a, 35 brotatably mounted around axes for front and rear at specified positionsof the movable guide rail members except for the highest movable guiderail member, the tops and the bottoms of the interlocking pinions areinterlocked with movable racks 37, 39 or fixed racks 38, 40,respectively, in this case, a tooth of said movable rack and a tooth ofsaid fixed rack are inclined in a front/rear direction of face width,and the interlocking pinions serve as a bevel gear for engaging with thetooth of the movable rack, and besides, axes for front and rear 36 a, 36b corresponding to the interlocking pinions are formed of fixed axes forfront and rear 41 a provided on the corresponding movable guide railmembers 17, 18 and eccentric cylindrical axis members 41 bexternal-insertedly fixed on the fixed axes for changeably adjustingangles around them, and moreover, the interlocking pinions adjust frontand rear positions on the corresponding axes for front and rear,respectively.
 6. A work carrier as claimed in claim 2, wherein said workcarrier comprises a reduction gear 20 for being inputted rotation of anoutput axis of said motor, a driving pinion 27 interlockingly connectedwith an output axis 20 a of the reduction gear 20 and freely rotatedalong a vertical surface for left and right at a specified position ofthe support table 10, a movable rack 31 long in a left/right directioninterlocked with the pinion and fixed on the lowest movable guide railmember, and a displacement detector 32 for detecting an operatingdisplacement of the output axis of the reduction gear on a path forcommunicating an operating displacement based on the rotation of themotor or an operating displacement in the arbitrary position by the sideof a communicating displacement terminus from the output axis.
 7. A workcarrier as claimed in claim 2, wherein said rail member interlockingmechanism is provided with a long fixed rack in a left/right directionfixed on said fixed guide rail member, movable racks long in aleft/right direction respectively fixed on said movable guide railmembers, and interlocking pinions 35 a, 35 b rotatably mounted aroundaxes for front and rear at specified positions of the movable guide railmembers except for the highest movable guide rail member, the tops andthe bottoms of the interlocking pinions are interlocked with movableracks 37, 39 or fixed racks 38, 40, respectively, in this case, a toothof said movable rack and a tooth of said fixed rack are inclined in afront/rear direction of face width, and the interlocking pinions serveas a bevel gear for engaging with the tooth of the movable rack, andbesides, axes for front and rear 36 a, 36 b corresponding to theinterlocking pinions are formed of fixed axes for front and rear 41 aprovided on the corresponding movable guide rail members 17, 18 andeccentric cylindrical axis members 41 b external-insertedly fixed on thefixed axes for changeably adjusting angles around them, and moreover,the interlocking pinions adjust front and rear positions on thecorresponding axes for front and rear, respectively.
 8. A work carrieras claimed in claim 3, wherein said rail member interlocking mechanismis provided with a long fixed rack in a left/right direction fixed onsaid fixed guide rail member, movable racks long in a left/rightdirection respectively fixed on said movable guide rail members, andinterlocking pinions 35 a, 35 b rotatably mounted around axes for frontand rear at specified positions of the movable guide rail members exceptfor the highest movable guide rail member, the tops and the bottoms ofthe interlocking pinions are interlocked with movable racks 37, 39 orfixed racks 38, 40, respectively, in this case, a tooth of said movablerack and a tooth of said fixed rack are inclined in a front/reardirection of face width, and the interlocking pinions serve as a bevelgear for engaging with the tooth of the movable rack, and besides, axesfor front and rear 36 a, 36 b corresponding to the interlocking pinionsare formed of fixed axes for front and rear 41 a provided on thecorresponding movable guide rail members 17, 18 and eccentriccylindrical axis members 41 b external-insertedly fixed on the fixedaxes for changeably adjusting angles around them, and moreover, theinterlocking pinions adjust front and rear positions on thecorresponding axes for front and rear, respectively.
 9. A work carrieras claimed in claim 4, wherein said rail member interlocking mechanismis provided with a long fixed rack in a left/right direction fixed onsaid fixed guide rail member, movable racks long in a left/rightdirection respectively fixed on said movable guide rail members, andinterlocking pinions 35 a, 35 b rotatably mounted around axes for frontand rear at specified positions of the movable guide rail members exceptfor the highest movable guide rail member, the tops and the bottoms ofthe interlocking pinions are interlocked with movable racks 37, 39 orfixed racks 38, 40, respectively, in this case, a tooth of said movablerack and a tooth of said fixed rack are inclined in a front/reardirection of face width, and the interlocking pinions serve as a bevelgear for engaging with the tooth of the movable rack, and besides, axesfor front and rear 36 a, 36 b corresponding to the interlocking pinionsare formed of fixed axes for front and rear 41 a provided on thecorresponding movable guide rail members 17, 18 and eccentriccylindrical axis members 41 b external-insertedly fixed on the fixedaxes for changeably adjusting angles around them, and moreover, theinterlocking pinions adjust front and rear positions on thecorresponding axes for front and rear, respectively.